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Full-Text Articles in Physical Sciences and Mathematics
Development Of A Low-Cost, Open Source Miniature Rotary Cell Culture System To Simulate Microgravity Within An Irradiated Environment, Elizabeth Vargis, Jr Dennison
Development Of A Low-Cost, Open Source Miniature Rotary Cell Culture System To Simulate Microgravity Within An Irradiated Environment, Elizabeth Vargis, Jr Dennison
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A major challenge for astronauts in long-duration space travel is combatting the hazardous spaceflight environment caused by microgravity and increased levels of ionizing radiation. Microgravity damages cellular DNA by increasing the production of harmful reactive oxygen species, while ionizing radiation damages DNA by creating double-stranded DNA (dsDNA) breaks. Cellular damage due to microgravity and radiation has been investigated using ground-based models, but most models consider microgravity and ionizing radiation alone, or asynchronously. Synchronous modeling better mimics spaceflight conditions and can be used to understand the combined effects of microgravity and ionizing radiation. However, commercially available devices to model microgravity and …
Meps Data Assimilation System, Robert W. Schunk, Larry Gardner
Meps Data Assimilation System, Robert W. Schunk, Larry Gardner
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For the current funding opportunity we propose to develop a master system that will enhance the user interface to the MEPS model and enable the scientific community to efficiently use the model. Furthermore, we will build and automate validation tools and improve the efficiency and robustness of the MEPS ensemble averaging scheme. Finally, we will explore the nest step toward a major advancement in MEPS b significantly improving the spatial resolution of one of the data assimilation models to explore meso- and small-scale features.
Aluminum Secondary Electron Yield, Jr Dennison, Phillip Lundgreen
Aluminum Secondary Electron Yield, Jr Dennison, Phillip Lundgreen
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Accurate modeling of spacecraft charging is essential to mitigate well-known and all-too-common deleterious and costly effects on spacecraft resulting from charging induced by interactions with the space plasma environment. This paper addresses how limited availability of electron emission and transport properties of spacecraft materials—in particular secondary electron yields—and the wide range measured for such properties pose a critical issue for modeling spacecraft charging. It describes a materials charging database being developed, which when used in concert with the strategies outlined herein for best practices for establishing optimized materials properties for spacecraft charging models and specific mission requirements and how these …
Open/Closed Boundary And Energy Cutoff Latitude Data For Papers 1 And 2, David Alan Smith
Open/Closed Boundary And Energy Cutoff Latitude Data For Papers 1 And 2, David Alan Smith
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Abstract for Paper 1: The open-closed boundary (OCB) defines a region of significant transformation in Earth's protective magnetic shield. Principle among these changes is the transition of magnetic field lines from having two foot points, one in each hemisphere, to one foot point at Earth, the other mapping to the solar wind (SW). Charged particles in the SW are able to follow these open field lines into Earth's upper atmosphere. The OCB also defines the polar cap boundary (PCB). Being able to identify and track the OCB allows study of several components of the geomagnetic system. Among them are the …
Spacetime Groups, Ian M. Anderson, Charles G. Torre
Spacetime Groups, Ian M. Anderson, Charles G. Torre
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A spacetime group is a connected 4-dimensional Lie group G endowed with a left invariant Lorentz metric h and such that the connected component of the isometry group of h is G itself. The Newman-Penrose formalism is used to give an algebraic classification of spacetime groups, that is, we determine a complete list of inequivalent spacetime Lie algebras, which are pairs (g,η), with g being a 4-dimensional Lie algebra and η being a Lorentzian inner product on g. A full analysis of the equivalence problem for spacetime Lie algebras is given which leads to a completely algorithmic solution to the …